Production of artificial silk



Patented Oct. 13, 1936 UNITED STATES PATENT OFFICE N0 Drawing. Application August 17, 1928, Serial No. 300,375. In Germany June 24, 1927 3 Claims.

The present invention relates to the production of artificial silk and artificial threads from viscose, which artificial silks or threads have a dull finish, and the subject matter of the invention is an improvement upon the process described in a copending application, filed by myself and Johannes Heck, Serial No. 197,509, filedJune 8, 1927.

As is well known, when viscose is squirted, in the form of a. very thin stream into a setting bath, the said stream of viscose is acted upon by the substances in the bath, usually acids or acid salts, to produce what is known as artificial silk. The artificial silk thereby produced usually has a very high luster, or glossy finish, which ordinarily exceeds the glossiness of real silk.

In accordance with the disclosure of the prior application above referred to, an oily material is first mixed with the viscose, and the mixture is converted into a suspension or very fine emulsion, after which the squirting operation is effected in the usual manner, and as stated in the said prior application, any of the usual setting baths, containing acids or acid salts, alcohols and the like, with or without neutral salts, glucose and similar substances can be employed.

It may be noted that it has heretofore been proposed to incorporate a lignoprotein, preferably lignoglutin, in a viscose spinning solution and thereby impart curling and felting properties to the product spun from the solution. The object of this proposal was evidently to obtain products of the nature of wool, whereas the present invention is concerned with artificial silk having a smooth dull or matt finish similar to natural silk without the aforesaid curling or felting properties which are effects entirelyinappropriate for artificial silk threads.

In accordance with the present invention I may use a proteid material such as albumen or casein, which can be dissolved in the viscose prior to the setting operation, and the said operation may be carried out before the usual ripening treatment if. desired. In a modification of the process I may employ, mixed with the casein, an inorganic material which is soluble in the viscose, such as barium hydroxide, or a mixture of casein and albumen may be used.

A distinguishing feature of the present invention from that disclosed in the said prior application is the fact that in the present case substances may be used which dissolve readily in the viscose, whereas in the said prior case, oils or oily materials are used, which do not readily dissolve in viscose. It will be obvious that the substances to be added to the viscose should not be substances that will react. with the viscose to form precipitates.

The following example is given for the purpose of illustration, and not for the purpose oi. limiting the invention thereto.

Example 1 A viscose is prepared in the ordinary Way, from a cellulosic material, caustic alkali and carbon bisulphide. 5% of. casein or albumen, calculated on the weight of the cellulose content of the viscose, is then added, and the mixture well stirred. The solution is then squirted, after maturing further if desired, into any of the usual setting baths. The thread can also be subjected to any of the usual after treatments. The threads so produced do not have a high gloss, and do not acquire a high gloss even after drying or after desulfurization. The threads produced can be dyed with sulfur dyes or vat dyestufis, also without producing a high luster.

It will be understood that various substances can be employed instead of. those above enumerated, and in general substances which are readily soluble in viscose are to be used, which I embrace in the class consisting of nitrogenous organic bodies which are soluble in dilute alkalies but insoluble in dilute acids, such as casein and the like. I may also use in admixture with such bodies soluble inorganic alkaline earth metal compounds, such as barium hydroxide, which are soluble in viscose or in dilute alkaline solutions.

I claim:-

1. A process of making artificial threads having a dull finish which comprises squirting a viscose containing a dissolved proteid and barium hydroxide, into a setting bath.

2. Process of producing artificial products suitable for the textile industry, which comprises introducing into a setting bath, a viscose containing a proportion of a proteid and a soluble inorganic alkaline earth metal compound, whereby a dull finish similar to natural silk is imparted to the product without boiling treatment.

3. Process of producing artificial products suitable for the textile industry, which comprises introducing into a setting bath, a viscose containing a proportion of a proteid and barium hydroxide.

BENNO BORZYKOWSKI. 

